TREATMENT
The purpose of treating glaucoma is to prevent further loss of vision because it is irreversible. A number of treatment methods are used depending on the patient’s condition. Treatments can range from simple medications like eye drop and pills to laser surgeries and eye operations. A combination of the above methods may also be used. The key to prevent vision from deteriorating is keeping IOP levels under control.
Eye drops may cause a burning sensation at first due to the antibacterial substance present in the medicine. However, the discomfort lasts for only a few seconds. It is vital that the drops be administered exactly as prescribed if the IOP level is to be kept low. Some drops with‘duration of action’ of six hours may be prescribed four times a day, to keep the drug effective for 24 hours. Eye drops are absorbed into the bloodstream so it is important to keep your doctor informed of other medications you may be taking.
Patients can minimize the absorption of drugs into the bloodstream and maximise the amount absorbed into the eye. They can do this by closing their eyes for one to two minutes after the administration of the drops and press gently against the nasal corner of the eyelids. The latter procedure closes the tear duct that drains into the nasal cavity.
Patients’ role in the treatment of glaucoma
It is important to be aware and involved in the glaucoma treatment, particularly when it is concerned with the eye drops which is the mainstay of the glaucoma treatment. The usage of eye drops should be consistence and generally lifelong. Patients who are aware, educated and know the importance and goal of the treatment tend to have high success rate to their treatment. If a person in the family has glaucoma, their family members are at high risk of having glaucoma as well and their sibling has about 20% risk, so they must get themselves checked. It would also be relevant for their children’s as they get close towards the age when you were first diagnosed. If is be good to keep your family members informed about the type of glaucoma which you were having.
Although there is no cure for glaucoma, with regular treating of glaucoma it is possible to controlled and can prevent or slow down further loss of sight.
Majority of the patients diagnosed with glaucoma are able to manage the condition successfully with the help of eye drops and at time with laser treatment. At the time of diagnosis the information gathered from test assessments and lifestyle and considering the type of glaucoma, doctors are able to determine the initial treatment.
Drugs and Possible Side Effects
This family of drugs include Pilocar, Carbachol, Echothiophate phospholine iodide, etc. These constitute eye drops which help clean up the eye’s drain and increase the flow of fluid from the eye. Pilocarpine comes in drops, gel (Pilogel), and slow-release (Ocusert) forms. These medicines may cause pain inside the eye or around it, including browache for a few days. Blurred vision and extreme myopia are very common in younger patients. Miotics reduce the size of the pupil and prevent dilation so dimness of vision, especially in dark environments can be expected.
Stronger miotics can cause stuffy nose, increased salivation, sweating and gastrointestinal problems. Drugs like epinephrine, epifrin (Eppy-N) can cause burning sensations, red eye, allergic reactions, palpitations, high blood pressure, tremors, anxiety and headaches. Dipivefrin propine acts like epinephrine but if used in very less concentrations can lessen the side effects
Common betablockers used in the treatment of glaucoma are Timolol Hemihydrate (Timoptic), Levobunalol (Betagan) and Carteolol (Ocupress). They cause fewer side effects in the eye but may have an adverse effect of existing pulmonary disease, slow down the pulse, cause difficulty in breathing, impotence, hair loss and reduce blood pressure. There can also be side effects to the central nervous system including dizziness, weakness, fatigue, insomnia, hallucinations, depression and loss of memory.
Beta-1 blockers like Betaxolol (Betopic) decrease the production of fluid in the eye. As they are selective beta-1 blockers, patients suffering from asthma or emphysema are safer from it. Apraclonidine (Iopidine) is used in laser surgery to prevent sudden upsurges in IOP caused by the treatment. Brimonidine (Alphagan) is a very selective alpha-2 adrenoceptor agonist, which reduces the production of aqueous humour and enhances uveoscleral outflow.
Brimonidine, administered twice daily with a dosage of 0.2% offers long-term control of IOP compared to a 0.5% dosage of timolol. Introduced in 1996, Briminodine is less likely to cause allergic reactions than apraclonidine
Latanoprost (Xalatan) increases the rate of outward fluid flow from the eye. Introduced in 1996, the drug acts differently from other agents and needs to be taken but once a day.
Though every drug has potential side effects, many people experience no side effects at all. In some cases, drops cannot control IOP, in which case pills may be prescribed in addition. Pills potentially have more side effects than drop and serve to lessen the production of aqueous humour. Pills are usually prescribed for two or four times a day. It is important that doctors treating any other condition you may have know the medications you are taking for glaucoma.
Among the more commonly prescribed drugs from this family are Acetazolamide (Diamox), Methazolamide Neptazane, etc. These pills reduce the inward flow of fluid into the eye and should be taken with meals to reduce the side effects. To minimise loss of potassium, nutrition can be reinforced by bananas or apple juice. Dorzolamide (Trusopt), introduced in 1995, is the first topical carbonic anhydrase inhibitor that seems to have similar side effects to these pills but with much lower frequency and severity.
Other side effects of carbonic anhydrase inhibitors can be frequent urination and tingling sensation in toes and fingers, but they disappear after a few days. Kidney stones may also develop but a serious consequence is aplastic anemia. Rashes, depression, fatigue and gastrointestinal problems are common. Potassium may deplete from the body when the drugs are taken with digitalis, steroids or chlorothiazide diuretics.
Medications
Medication reduces the production of fluid or the inflow of the aqueous fluid into the eye, or by increasing the outflow pathway which allows the aqueous fluid to drain more effectively from the eye. There are some medication which performs both the activity. One of the critical factor is that it needs cooperation from the patients for the medication.
Usage of eye drops is the most common form of treatment and it should be used as per the prescription. The drops would vary depending on the patient and the type of glaucoma so that it suits the best for the treatment.
Remember: Drops needs to be used as per the prescription so that the best results can be achieved.
Open-angle glaucoma may be treated using Oral Medication. This medication is normally used for a short period of time as it would reduce its effectiveness over a period of time.
Surgical Procedures
Surgery is the only option when medication is not effective or has severe side effects. The most popular form of surgery is laser. It is also the primary form of surgery, as an intermediary procedure before conventional surgery may be required. For open-angle glaucoma, the most preferred surgery is called trabeculoplasty. It is a small outpatient procedure that takes between ten and twenty minutes and is painless. A high-energy laser beam is focused on the drain of the eye. The intensity of the heat causes certain areas of the drain to shrink. This stretches open the surrounding areas, allowing the fluid to flow more freely.
Patients are free to go home immediately and resume normal activities, but the doctor will need to monitor IOP levels a couple of hours later. Eighty per cent of all patients respond so well that conventional surgery is delayed or ruled out altogether. It takes a few weeks for the pressure-reducing effects of the surgery to be noticeable, during which time patients need to continue medication. Some patients are eventually able to come off the medicines completely. Contrary to popular thought, laser surgeries do not result in cataracts.
A. Laser
Laser surgery can be used to treat some cases of glaucoma. Different types of laser is used to treat open and closed angle glaucoma. Laser can be used on iris or the trabecular meshwork to allow aqueous fluid to flow more effectively within the eye and will help better in the normal drainage channel present within the eyes. Unlike incisional surgery, Laser surgery will not create a physical opening between the inside and outside of the eyes.
Laser Peripheral Iridotomy is a treatment that is performed on patients who has or has a risk of developing acute angle closure or who has chronic narrow angle glaucoma
Selective Laser Trabeculoplasty (SLT) is a procedure which is performed when eye drops do not stop deterioration in the field of vision. In many cases, eye drops need to be continued after laser procedure.
Cyclodiode Laser Treatment causes cyclodestruction, which destroys a portion of the ciliary body, an organ in eyes which produce aqueous fluid. Which can reduce the amount of fluid produced and this would reduce the pressure inside the eye.
B. Incisional Surgery (trabeculectomy or glaucoma drainage device)
Incisional surgery may be required sometimes if the disease doesn’t come to control even after using the medications or laser, or if the patient is intolerant towards the above mentioned treatment. The urgency for incisional surgery would depend on the aggressive or advanced stage of glaucoma. Incisional surgery creates an alternate pathway for the aqueous fluid to exit the eye. This fluid is made to drain physically by creating a pathway from within the eye to the space just under the whites of the eye under the upper eyelid. Aqueous fluid will be then absorbed by the fine blood vessels that are present naturally on the whites of the eye.
Patients may not see with their normal visual acuity for a few weeks after the surgery. Though trabeculectomy is itself a relatively safe procedure, roughly one-third of patients develop cataract within five years. However, most patients do not have to take glaucoma medications post surgery. In ten to fifteen per cent of cases, patients are required to undergo another surgery.
- Glaucoma drainage devices and tube implant glaucoma surgery- A tube–shunt drainage operation is performed sometimes in situations where it is difficult to control or complex glaucoma’s, especially in the situation where other sorts of surgery may have failed or is likely to fail.
Tube-shunt surgery (Seton glaucoma surgery) is a type of surgery where a flexible plastic tube with an attached silicone drainage pouch is placed in the eye so that the fluid (aqueous humor) gets drained from the eye. This type of surgery is performed usually when trabeculectomy has failed. If a person already has a scar tissue or is likely to form scar tissue in the eyes, this type of surgery can be performed in the beginning. There are many types of drainage implants. Some of them are Molteno, Baerveldt and Ahmed. They all work in similar manner.
C. Recent Advance in Surgery
Minimally Invasive Glaucoma Surgery (MIGS), is the latest advance in surgical treatment for glaucoma which aim to open up the trabecular meshwork or Schlemm’s canal so that more fluid drains from the eye.